Vibrator



G. L. GLEGG Dec. 6, 1949 VIBRATOR Filed Jun 1a, 194e wml@ Patented Dec. 6, 1949 vIBnA'ron 4Gordon Lindsay Glegg, London, England, assignor to The SquareGrip Reinforcement Company (London) Limited, London, England, a British company Application June 1s, 1946, serial No. 677,638

, In Great Britain May 12, 1944 Section 1, Public Law 690, August 8, 1946 Patent expires May 12, 1964 6 Claims.

-This invention relates tov vibratorsthatris to say",l to apparatus for originating mechanical vibrations-@and its primary. object is to provide vibrators having certain .advantageous` features', particularly the capability 'of originating vibrations of higher frequencies than those obtainable by known apparatus. 1

' According tothe invention, a vibrator com prises an inner member provided with a plurality of protuberances upon its; periphery which protuberances are directed'outwardlyV from the4 longitudinal axis of thesaid inner' member, which inner member is. contained loosely. in a hollow outer member with .'whoseinner periphery are. associated a plurality of impact. members which during. operation of the vibrator are movable relatively to the said outer member and which formprotuberances that are directly inwardly towards the longitudinal axis of theouter mem,- ber, means being provided to cause such relative motion between theA inner member; and-the outer member asv shall constitute virtual rotation of theinner -member with-in the outer member, the arrangement-being such that during the said rela-4 tive motion there occur rapidly repeated impacts. between the inner member and the said-'protuberances movablyassociated with the outer member, whch'impacts originate` vibrations ofthe outer member.

Preferably the outermost points upon the protuberances of the said inner member are ar-v ranged substantially circumferentially'in respect o f the longitudinal axis of the inner member, and the innermost points upon the impact members associated with the said outer member are arferences around which yare arranged thesa'id innermost points of' the outer member.'

vAccording to one embodiment ofthe' invention,

the said inner member isA a' rotor provid'ed'w'ith pluralityl of" lobes which extend radially in vrespect of the axis o1' the rotor,are equally spaced each from the next and are or equal radial length. The said outer vmember isa stationarytubular casing provided with a plurality`v of im-l pact members arranged circumferentially around the interiors-urfacethereof equally spaced each from the next and movable but notradially dis-' placeable in relation to the said tubular casing; from the longitudinal" axis of which casing' thel A 2 impact surfaces of the said impact members are equidistant.

The' said rotor` is not only rotatable in relation to the impact members, but is. also capablev of oscillating or reciprocating laterally, that is, in directions transverse to its own longitudinal axis. Y

The arrangement is such that when the rotor is rotated the lobes thereof strike in rapid succession upon the impact members so that the tubular casing is caused to vibrate.

Other featuresof the invention will be particularly described hereinafter and set forth in the appended claims.

In order that the invention may be clearly understood and readily carried into effect, one embodiment of it will now be fully described with reference to the accompanying drawings, in

which- Figure l represents a cross-sectional end elevation of a vibrator, on the line I-I of FigurevZ;

Figure 2 represents a cross-sectional front elevation of the same vibrator; and

- Figures 3 and 4 are diagrammatic representa-A tions of variant forms of vibrator.

In the vibrator according to Figure 1, the inner member takes the form of a rotor I I which comprises a spindle I2, extended at vone end I3 to be connected toY suitable means for driving the rotor H, which must be so connected to: the driving means as to be allowed freedom to oscillate laterally. The end I3 may, for example, be associated with a loose flexible connection such as a universal joint. At its opposite extremity the spindle I2 is formed with an operative end It. which in the present instance-is substantially tri-` angular having three rounded corners I5. These rounded corners I5 may be regarded as: protuber. ances or lobes extending from. a reduced end porm tion of. the rotor Il.v In a slightly developed' form of such a rotor the corners or lobes are so` rounded as to vbe ,cross-sectionally semicircular" at the ends, and the hollows between lobes are rounded to concavity. i

`The rotor II is housed within a tubular casing I6 with which the said impact members are 'associated` lIn the present instance the impact members are four rollers I'Iadapted to roll upon. a hardened steel sleeve I3 fitted rigidly within the casing I6. The four rollers I'I are maintained equidistant each from the next and with their axes parallel with the axis of the rotor II by means of two locating rings I9, each roller Il being provided 'at each end with a small axial gudgeonZ adapted to t rotatably into a bear- 3 ing hole 2I in a locating ring I9, each locating ring I9 being accordingly formed with four bearing holes 2|, each equidistant from the next.

The casing I6 is closed at the operative end by a conical closure 22, which may be integral with the casing I6, as illustrated, or be in any suitable manner aflixed thereto. At the driving end the casing I6 is closed by a self-aligning ball bearing 23 which supports the spindle I2 in such a manner that the latter is free not only to rotate but also to move slightly out of parallel to the casing I6 in accordance with oscillations of the operative end I4.

The arrangement is such that as the rotor II rotates and any corner or lobe I makes impact with a certain impact member or roller I1 the v rotor is allowed to rebound so as to make impact with another impact member or roller I'I on the opposite side of the tubular casing I6.

By modification of the form of vibrator just described, the outer-member may comprise balls instead of rollers, and these balls may be adapted to revolve around the longitudinal axis of the outer member as well as rotating upon axes of their own. It is not an essential feature of the invention that such rollers or balls should revolve as well as rotateobviously locating means for rotatable rollers or balls could easily be arranged to be fixed in relation to the outer member: it is, however, essential, 'whether rollers or balls are used, that they be so associated with the outer member as to be movable relatively thereto.

An arrangement in which balls are adapted to rotate and revolve simultaneously is illustrated diagrammatically by Figure 3. Here four balls IM are arranged to roll upon the inner surface of the tubular casing I6, and are maintained equidistant each from the next by a locating cradle 25, which in this case is a hollow cylinder pierced radially with four holes adapted to hold rotatably the balls 24. The rotor I4 is exactly as that of Figures 1 and 2, and its rotatory and oscillatory function is the same. Regarded in end view, as depicted in Figure 3, if the rotor I4 revolves clockwise as indicated, the ballsY 24 will revolve counter-clockwise, and by rolling upon the casing I B they will cause the locating cradle 25 to revolve clockwise.

It may be found practicable to arrange that rollers constituting impact members are power driven.

Therrinvention is not limited to the use of a rotor with only three lobes or an outer member comprising four impact members. Thus a rotor may be of substantially square cross-section and may co-operate Awith either three or five impact members. It may be found practicable to use a rotor provided with lobes of any number within reason, provided that this number is either more or less than the number of impact members employed.

In Figure 4 is represented diagrammatically a construction in which a two-lobe rotor 26 is `adapted to co-operate with three rollers I1 held in place by locating rings 21 which correspond generally to the locating rings I9 of Figures l and 2 but are formed with only three bearing holes 2| for the gudgeons 20 of the rollers I1.

It appears that if a three-lobe rotor is used in an outer casing comprising four imp-act members, the impact members being fixed, then a single complete rotation of the rotor causes twelve separate impacts between the rotor and impact members. If the impact members revolve with the rotor, the number of impacts per rotation of rotor is somewhat reduced; but by suitably designing the sizes of the various components ten vibrational impulses can be obtained per rotation of rotor. As vibrators in common use produce only one vibrational impulse per rotation of shaft, it follows that by the application of the invention the vibrational frequency obtainable is multiplied by ten. Thus if by stepped-up electric drive the rotor of a vibrator according to the invention is driven at the practicable speed of about 6,000 revolutions per minute, the apparatus Will produce vibrations of frequencies of the order of about 60,000 impulses per minute.

It may in some cases be found advantageous to arrange that the said inner member, instead of being a rotor, is fixed, and the said outer member is caused to revolve around it.

The invention is particularly adapted for application to vibrators used in the placing of concrete, in which application high vibrational frequencies are eminently desirable. In this connection a valuable characteristic of a vibrator according to the invention results `from the fact that the vibrations produced take the form of abrupt impulses or jerks, with which is associated particularly large acceleration.

An important advantage provided by such ann forms of concrete vibrator. If balls or rollers are used las impact members they can be of greater diameter and their number or length may be such that the stresses upon them are more widely distributed than in the case of the balls or rollers used in the bearings of the driving shaft. Comparatively, therefore, a vibrator according to the invention is highly economical in upkeep, in addition to possessing the outstanding advantage of providing greatly increased vibrational frequencies.

I claim;

1.` A vibrator comprising a casing, a rotor in said casing, said rotor having at least one lobe disposed on its periphery, such lobe extending radially outwards from the longitudinal axis of said rotor, a plurality of impact members disposed within said casing and around the lobed portion of the rotor, and a bearing which supports the said rotor near one end thereof and allows the rotor to be rotatedabout its longitudinal axis whereby the rotor may whirl transversely of the casing and the said lobe may encounter the impact members and cause the rotor to strike impactively against said members, thereby producing the desired vibration of the casing.

2. A vibrator comprising a rotor, a plurality of lobes formedonatportion thereof, the said lobesv projecting radially outwards from the longitudinal axis of said -rotor and terminating with rounded contours, a casingvhousing said rotor, a plurality of impact members within the casing, means for locating said members in positions around the said lobes, said means permitting the impact members to roll on a surface associated with the inner surface of the casing, and a self-aligning bearing which supports the said rotor near one end thereof and allows the rotor to be rotated about its longitudinal axis and whirled transversely of the casing, whereby the said lobes encounter the impact members and cause the rotor to strike impactively against said members, thereby producing the desired vibration of the casing.

3. A vibrator according to claim 2 in which the radially extending extremities of the lobes lie substantially circumferentially around the longitudinal axis of the rotor and the innermost points of the impact members lie substantially circumferentially around the longitudinal axis of the casing.

4. A vibrator according to claim 2, in which the means for locating the impact members in position around the lobes is a cage which is rotatable about the longitudinal axis of the casing and which maintains the said impact members around the said axis at substantially equiangular intervals between adjacent members, and in which the lobes are disposed around the rotor with equiangular intervals between adjacent lobes.

5. A vibrator according to claim 2, in which the impact members are rollers.

6. A vibrator according to claim 2, in which the impact members are balls.

GORDON LINDSAY GLEGG.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS 

